To start with, some informations about EPOXI's flyby www.lpi.usra.edu/meetings/acm2008/pdf/8165.pdf
Spectral characteristcs sd-www.jhuapl.edu/weaver_projects/weaver_new_contour/hartley2/colangeli_aa99.pdf and www.lpi.usra.edu/meetings/thermal99/pdf/3010.pdf
Interesting paper on Harley 2's nucleus. It seems to be a mere 800 m across and active over the whole sunlit surface (this is quit unusual, most comets being active over at most 10-20 per cent of their surface) www.oamp.fr/lam/catalog/comets_090304/fichiers/publications/pdf/iras_hartley2_web.pdf